The present invention relates to novel solid state radioluminescent compositions and light sources. The United States Government has rights in this invention pursuant to Contract No. DE-AC04-76DP00789 between the United States Department of Energy and AT&T Technologies, Inc.
Radioluminescence (RL), or the emission of light stimulated by radioactive decay, is well known.sup.1. The phenomenon is widely employed in scintillation detectors, where the quantification of emitted light allows the measurement of radiation fluxes.sup.1,2. RL is also used in devices to produce light as an alternative to conventional electric light sources. RL lights have typically taken two forms, i.e., gas tubes or paints. In gas tube RL technology.sup.3,4 a glass tube is coated on the inner surface with an inorganic phosphor (such as ZnS), filled with T.sub.2 gas, and sealed. The maximum brightness of these lights is bounded: self-attenuation of betas by the tritium gas increases with increasing pressure, so that scaling of light output from these devices by simply increasing the pressure and/or internal volume of the tritium reservoir is limited.sup.4. In addition, the efficiency of these prior art lights suffer because the phosphor and tritium residues exist in different phases, so that not all beta particles reach a potentially luminescent site in the phosphor. Another practical consideration with this technology is that the tubes are subject to breakage, which raises safety concerns regarding the release of T.sub.2. RL paints have typically made use of an inorganic phosphor together with a radioactive isotope such as promethium-147, tritium, or radium-226.sup.5. The brightness of such paints is limited by the opacity of the phosphor.